Warm air furnace



April 9 1940. A. P. LIVAR WARM AIR FURNACE Filed June 17, 1938 3 Sheets-Sheet 1 INVENTOR. flLLE/V P LIV/IR W VM W ATTORNEY A.

April 1940- A. P. LIVAR WARM AIR FURNACE Filed June 17, 1938 3 Sheets-Sheet 2 INVENTOR'. 41. w P LII/14R ATTORNEY.

- April 1940- A. P. LlVAR WARM AIR FURNACE Filed June 17, was

3 Sheets-Sheet 3 INVENTOR. ALLEN P LII/HR ATTORNEY.-

BY W M, vi Ma:

Patented Apr. 9, 1940 OFFICE} WARM AIR FURNACE Allen P. Livar, Dayton, Ohio, aasignor, by mesne assignments, to Chrysler Corporation, Highland Park, M.ich., a corporation of Delaware Application June 11, 1938, Serial No. 214,1

3 Claims.

This invention concerns improvements in the construction, arrangement and details of a warm air furnace which may be fired by any suitable means such as oil or gas burners.

' The primary purpose of this construction is to provide the most efiicient heat transfer between the flue gases and the air to be warmed, whereby a small, light, inexpensive furnace, from one- -third to one-half .cheaper and smaller than existing furnaces of the same capacity, maybe provided for house heating. Another purpose of the present invention is to provide 'a furnace which is easily assembled and which will occupy as little space as possible in order that the furfloor to be provided with warm air; whereas previous furnaces have been of such size that naces may be installed in utilityclosets on the air to bwarmed. A fifth purpose of the present invention is toprovide a furnace wherein the radiant surfaces are surrounded by moving choring a baille in the heat exchangers; Fig. 6 is a side view on a small scale of a portion of the present furnace having an oil-burning device attached thereto; and Fig. 7 is a view similar to view 6 showing a portion of a furnace having a gas burner attached thereto and illustrating the interchangeability of firing means for the present type of furnace.

The furnace construction comprises a jacket Ill which'surrounds the firebox, heat exchangers, blowers and filter comprising the operating parts of the furnace, and whichis provided with an inlet II which may be connected to a duct or left open to the room. The-inlet II is preferably adjacent the bottom of the furnace,.and the outlet i2 is preferably adjacent the top of the furnace in order to. take advantage .of natu-' ral draft in addition to forced draft provided by blowers I3 located in the bottom portion of the furnace and driven by a suitable motor It. The blowers draw n inward through the opening u, and through a filter i5 interposed between the opening and the inlet to the blowers. The blowers and motor are suspended from a blower deck -deck it, together with the lower surfaces of the firebox and heat exchangers, form a plenum chamber into which the air is .discharged by streams of air and are suitablyspaced from the,

jacket of the furnace in order that the furnace jacket may not become overheated, some of the spacing and insulation being provided by heat exchanging surfaces which are in tumcontacted by moving streams of air to be warmed. A sixth purpose of the present invention is to provide air to be warmed 'L.

the blowers. II. I An access door 2| isprefe'rably provided in order to service the motor l4-,an d blowers It, the same being provided with removable fastening means 22.

The upper ends of legs I! are joined by angles 25 upon .which are supported the firebox and heat exchanger construction. The firebox preferably comprises a rectangular enclosure 26 of considerable height with respect to its cross-sectional'dimerisions, having parallel upwardly extending walls except for one wall (preferably the rear wall). which extends upwardly-to a} point adjacent the hottest flame region arni then- -di'- agona'ly inward andu-pward toward the opposite following specification, taken in connection-with als refer to like parts throughout. In the drawings, Fig. 1 isa front elevation of one size of furnace embodying my present invention; Fig, 2 is a side elevation of. the furnace shown in 60 Fig. 1; Fig. 3 is a cross section taken along line 3-3 of Fig. 2 looking in the direction-of the 4 the accompanying drawings wherein like numer- The heat exchangers are substantiall rectanguarrows; Fig. 4 is a cross section taken along line 4-4 of Fig. 2 looking in the direction of the arrows; Fig. 5 is a vertical section taken along I line [-5 of Fig. 3, showing the means of'anwall to form an inclined crown sheet 21 above the hottest portion of the: fiame rising upwardly from the. burner 28. The upper front comers of the firebox arejprovidedwith laterally extend ing lines 29 'which'extend into the upp r front corners of. parallel heat exchangers 30 'and SI.

lar in shape and of the same .height"=-as theflre-j box, narrow in width, and extending front to rear of the furnace from a point adjacent thgx frontwall of the firebox to a-point rearwardl'y of the rear of-athe rear exhausted through a smoke stack ll.

corners of the heat exchangers are joined by a lateral exhaust flue 32 which is preferably triangular in cross section as formed by extending the top and rear walls of the heat exchangers, and an inclined flue sheet I! extending inwardly and upwardly, and parallel to the crown sheet 21. The heat exchangers are, spaced from the jacket walls in order to provide passages for moving streams of air entirely around all of the heating surfaces, and the heat exchangers and rear wall of the firebox provide a passage 34 of substantial dimensions extending upwardly into the inclined, forwardly extending passage 35 defined by the crown sheet 21 and flue sheet 33 whereby to provide means for moving a substantial quantity of air over the hottest portion of the firebox. The heat exchangers are laterally spaced from the side walls of the firebox to provide passageways for substantial quantities of air adjacent the radiant side walls of the firebox, andthere is likewise a substantially large passage adjacent the front wfils of the firebox and heat exchangers. All of these passages lead upward- Iy into a free space above the top of the firebox and heat exchangers,and the air moves through portion of the jacket.

The heat exchangers are provided with baffies 40 which are fastened to the top wall thereof and extend downwardly toward the lower wall thereof alonga line substantially dividing the heat exchangers into two vertical sections, the forward section conducting the hot flue gases downwardly from the lateral fiues 29, and the rearward section conducting the cooler fiue gases upwardly into the exhaust flue 32 where the parallel streams of flue gases are combined and It is to be noted that the blowers It are preferably mounted so as to throw the greatest volume of air forwardly into the plenum space whereby a greater quantity of moving air will tend to wipe across the front of the firebox and the forward portions of the heat exchangers than at the rear of the firebox and heat exchangers.

The firebox is preferably provided, with a relief opening and vent passage ll which is closed by a gravity-actuated explosion door I! as is usual in furnace construction. The heat exchangers are also preferably provided with forwardly extending cleanout es 41 which extend through the jacket and are closed by removable plates in order that any soot collected in the heat exchangersmay be removed from time to time.

The baffles ll are preferably rigidly fastened to the top surface of the heat exchangers and hang downward therein, and the lower ends sealed thereto by an asbestos gasket 62.

arocyos thereof are hooked at 6| about bolts 50 passing through the walls of the heat exchangers. Expansion of the baflies 40 is permitted by the loose connection, the baifles being guided by the bolts 50 and the hooked lower ends 5|. The bolts act as tie-rods to prevent the walls of the heat exchangers from reverberating and the baffles act as spacers for the tie-rods.

The burner 28 is suitably mounted in the firebox by rigidly fastening the same to a removable cast-iron burner plate 80 which is fastened to the front wall of the firebox by bolts BI and As seen in Figs. 6 and '7, the burner plate Bil may be replaced by a suitable burner plate 60' which is so fashioned as to provide a means of supporting an oil burner 28' instead of the gas burner 28.

The furnace may be controlled by any suitable automatic or manual control system, as is well known in the art, the, control system being no part of my present invention. The present invention is fully illustrated in the accompanying drawings and described in wthe foregoingspecification, and it should be readily apparent to those skilled in the art that the same permits of modification in arrangement and detafl, all of which are considered a part of my invention as determined by the scope of the following claims.

I claim:

1. A warm air furnace comprising a substantially rectangular firebox having an inclined crown sheet, a substantially rectangular heat exchanger of substantially the same height as said firebox at each side of said firebox and spaced therefrom, a lateral flue extending from each of a pair of adjacent upper corners of said firebox near the top thereof and providing passageways for flue gases to pass from said adjacent upper corners of said firebox into the upper adjacent corners of said heat exchangers, a baflle in each heat exchanger extending downward from the top wall thereof and ending above the bottom wall thereof whereby to divide each heat exchanger into a downwardly extending portion and an upwardly extending portion to cause the fiue gases to flow downward then upward through said heat exchangers, a lateral: substantially triangular exhaust flue Joining the other upper corners of said heat exchangers, and i said side of said exhaust flue projects beyondthe adjacent side of said firebox in order to divert an upwardly movingstream of air into said air. duct. v

3. The structure set forth in claim 1, in combination with a jacket enclosing said firebox and fiues and spaced therefrom in order to define air passages surrounding the heat exchanging sur= faces, said jacket being provided with an outlet.

opening for the warm air located above thetop of said firebox and adjacent the outlet to said airduct. I

, ALLEN P. man. 

